Leak-fuel collecting and detecting device for an internal combustion engine

ABSTRACT

The present invention is concerned with a device for collecting and detecting leak-fuel in the fuel discharge pipe connecting the injection pump with the injector of the corresponding cylinder of an internal combustion engine. The device comprises a hood tightly covering the head of the injection pump and through which pass said delivery pipe and the sheath surrounding it, and leakfuel discharge means for discharging the leak-fuel accumulated in the internal volume of said hood. Preferably, said discharge means comprise a collecting vessel provided with a warning device.

United States Patent Kuhn et al.

[ Jan. 8, 1974 LEAK-FUEL COLLECTING AND DETECTING DEVICE FOR AN INTERNAL COMBUSTION ENGINE Inventors: Karl Walter Kuhn,

Saint-Germain-en-Laye; Marcel Pierre Ernest Marie Corbin, LIsle Adam, both of France Assignee: Societe DEtudes Machines Thermiques, Saint-Denis, France Filed: Mar. 14, 1972 Appl. No.: 234,513

Foreign Application Priority Data I Am. 15, 1971 France 7113340 U.S. Cl 123/32 R Int. Cl. F02m 51/00 Field of Search 123/32 R, 139 AK References Cited UNITED STATES PATENTS Hansen et al. 123/32 R 3,194,221 7/1965 Dinger et al. 123/32 R FOREIGN PATENTS OR APPLICATIONS 42,814 3/1938 Netherlands Primary ExaminerLaurence M. Goodridge Assistant Examiner-Cort Flint Attorney- Kenyon & Kenyon Reilly Carr & Chapin ABSTRACT The present invention is concerned with a device for collecting and detecting leak-fuel in the fuel discharge pipe connecting the injection pump with the injector of the corresponding cylinder of an internal combustion engine. The device comprises a hood tightly covering the head of theinjection pump and through which pass said delivery pipe and the sheath surround ing it, and leak-fuel discharge means for discharging the leak-fuel accumulated in the internal volume of said hood. Preferably, said discharge means comprise a collecting vessel provided with a warning device.

8 Claims, 4 Drawing Figures PATENTED JAN 8 I974 SHLU 1 [If 3 bustion engines equipped with one or several such devices.

It is known that the discharge pipe connecting the injection pump with the injector is usually surrounded by a sheath with an annular spacing between the latter and the said pipe. One end of the said sheath is sealingly connected with the injector into which it is introduced, whereas the other end of the sheath opens freely into the ambient air or is connected with a branch pipe leading to a leak-fuel collecting vessel, thus enabling the leak-fuel resulting from the high pressure in the said pipe (from 250 to 800 kg/cm 2) and from defects in the fluid tightness of the couplings and/or joints to be conveyed out of the most dangerous region.

Without such a sheath there would be a risk of mixing of the leak-fuel with the lubrication oil lying on the various engine members and/or a risks of fire resulting from contact with heated portions thereof.

Although the said risk are considerably reduced in the presently known devices using such a sheath, a drawback to the said devices is that they require a great number of couplings and/or threaded piping assemblies and they do not collect the leak-fuel proceeding from the injection-pump head.

The device according to the invention enables the said drawbacks to be avoided.

The device is of the type comprising a sheath surrounding the fuel delivery pipe and sealingly connected with the injector, and is characterized in that it com-- prises a sealed hoodcovering the pump head, into the internal volume of which opens the said sheath, and means of discharge of the leak-fuel accumulated in the said internal volume.

According to a preferred form of embodiment of the invention, a collecting vessel is connected with the internal volume of the said hood and provided with a warning device adapted, in particulan'to rapidly warn of an important fuel leakage.

According to one feature of the invention, the said collecting vessel is provided with a large overflowopening enabling the leak-fuel to flow out in case of important leakage, the said opening being operated only after an important amount of fuel has entered and been maintained in the said vessel. However, in order that leakage of small importance, but occurring usually in a continuous manner, should not partake in the filling of the collecting device and should not cause the warning device to be operated after a certain time even in the absence of more important leakage, the said collecting vessel is advantageously provided at its bottom with a small opening enabling the fuel resulting from the said leakage of small importance to flow out.

According to an advantageous form of embodiment, a plurality of said hoods provided on the various injection pumps may be connected through a suitable network of pipes to one and the same collecting vessel, the mode of grouping depending in particular upon the number of cylinders equal to the number of injection pumps and upon the relative arrangement of the said cylinders.

' Other features and advantages of the present invention will appear as the following description proceeds. In the appended drawings given solely by way of example:

FIG. 1 is a general diagrammatic view of a collecting and detecting device designed according to one form of embodiment of the invention and used in connection with the cylinders of a Diesel engine, the said view being a view in profile at the level of the engine block; FIG. 2 is an axial sectional view of the upper portion of one of the injection pumps of the said engine;

FIG. 3 is a top view of the upper portion of the injection pump of FIG. 2; and

FIG. 4 is a vertical sectional view, upon the line IV-IV of FIG. 1, of the collecting vessel.

As shown in FIG. 1, a leak-fuel collecting and detecting device according to one form of embodiment of the invention comprises a fuel collecting vessel 1 connected, through a pipe network 2 comprising a collector 2a and elementary pipes 2b, 2c, with the upper 'portion of injection pumps 3a, 3b associated respectively with engine cylinders 4a and 4b.

Referring now to FIGS. 2 and 3, it is seenthat on the upper portion 4 of a pump such as 3a is sealingly fitted,

by means of an interposed seal 5, a hood 6 comprising a cone-shaped cap 6a and a tubular extension 6b, the

said cone-shaped cap being provided at its top with a seal 7, through an axial opening 8 of which passes a sheath 9 surrounding a pipe 10 through which the fuel is delivered by the injection pump into the corresponding injector (not shown). In the lower portion of the hood 6 is provided an orifice 11 with which is connected the pipe 2b (see also FIG. 1) conveying the leak-fuel to the collector 2a and the collecting vessel 1. In FIGS. 2 and 3 is also shown a tightening collar 12 provided with a tightening screw 12a enabling the hood 6 to be firmly and sealingly retained on the upper portion 4 of the injection pump 3a, and the fixing lug l3 and the clamp 14 holding the assembly formed of the delivery pipe 10 and its sheath 9.

FIG. 4 shows the internal structure of the collecting vessel 1 into which the leak-fuel is conveyed by the collector 2a. It is seen that the body of the latter is essentially formed of a casing 1a on which is adapted a removable cover lb retained by screws such as 15 and provided with an inspection orifice 16a closed by a threaded plug 16b. In another orifice 17 of cover lb-is fitted a bracket 18 carrying, on the one hand, a flexible blade 19, the free end 19a of which forms an electric contact, and, on the other hand, an arm 20 mounted pivotably at one end about a horizontal axis on the said bracket and terminating at its opposite end with a float 21, the external surface of which also forms an electric contact adapted to close a circuit when applied against the electric contact 19a, the electric circuit thus closed being adapted to operate a warning device, such as for instance a siren, connected electrically with the terminals 22.

At the bottom of the collecting vessel 1 is mounted a pipe coupling 23 having a small opening for continuous outflow of the fuel resulting from leakage of small importance.

The collecting vessel 1 is also provided with a pipe coupling 24 (FIG. 1) defining a large overflow-opening for the fuel resulting from important leakage.

The device shown in FIG. 1 also comprises fuelleakage sighting devices, such as that shown at 25 on 5 the pipe 2b. The device 25 comprises a cylindrical body extending along a substantially vertical axis 25a, a window 25b of transparent material and the end of the upper section of pipe 2b which is so bevelled as to form a whistle 25c. The internal volume of the body 25a, into which opens the whistle 250, communicates at its top with the lower section of the pipe 2b. It is readily understood that such a device enables direct observation of leakage even if the latter is of small importance, since in this case the shape of the whistle enables the fuel proceeding from the hood 6 to be concentrated in the form of large drops dripping always at the same place from the pipe 2b.

The device illustrated in FIGS. 1 to 4 operates as follows.

The fuel leaking in the region a where the sheath 9 stops (HO. 2), as well as that leaking in regions b,, 12 where the discharge pipe 10 proper is connected with the upper portion of the injection pump 3a, are collected in the internal volume of the hood 6 and flow through the orifice 11 into the pipe 2b and then into the collector 2a. Likewise, the leak-fuel proceeding from the pipe connecting the injection pump 3b with the corresponding injector is collected in the pipe and then in the collector 2a, so that the leak-fuel related to cylinders 4a and 4b are integrally conveyed into the collecting vessel 1. As long as the leakage is of small importance, the leak-fuel flows continuously through the pipe coupling 23 and the warning device is not operated, the said leak-fuel being eliminated progressively without involving any danger. If for any reason whatsoever the leakage becomes more important, the level of the fuel in the collecting vessel 1 rises progressively. When it reaches a predetermined height corresponding substantially to the level of the said overflow opening, the float 21 actuates the electric contact 19a which itself actuates the warning device in order that the engine may be stopped immediately or any danger resulting from the important fuel leakage may be averted by any other suitable means; the excess fuel may freely escape through the overflow opening 24 as long as the appropriate operation is not performed to avoid the said important leakage.

The location of fuel leakage may be determined by means of the sighting devices which, as in the case of the sighting device 25 shown in FIG. 1, indicate in particular whether the leak-fuel originates from the injection devices of the engine.

Of course, the invention is by no means limited to the form of embodiment described and illustrated, which has been given by way of example only. in particular, it comprises all the means constituting technical equivalents to the means described as well as their combinm tions, should the latter be carried out according to the spirit of the invention.

What is claimed is:

1. Device for collecting and detecting fuel leakage in a fuel delivery pipe surrounded by a sheath and connecting an injection pump with the injector of the corresponding cylinder of an internal combustion engine, said device comprising a sealed hood covering the head of the injection pump and through which pass said delivery pipe and said sheath, the latter terminating in the internal volume of said hood, leak-fuel and discharge means for discharging the leak-fuel accumulated in said internal volume, said leak-fuel discharge means comprising a collecting vessel connected with the internal volume of said hood and provided with a warning device.

2. Device according to claim 1, characterized in that said collecting vessel is provided with a level detector comprising a float mounted on a pivotable arm and adapted to actuate said warning device.

3. Device according to claim 1, characterized in that said collecting vessel is provided with a large-sized opening for the overflow of fuel resulting from important leakage.

4. Device according to claim 1, characterized in that said collecting vessel is provided at its bottom with a small-sized opening for the outflow of fuel resulting from leakage of small importance.

5. Device according to claim 1, characterized in that said leak-fuel discharge means comprise a discharge pipe opening into the upper portion of said collecting vessel and connected with the lower portion of the internal volume of said hood, said collecting vessel being located below the level of the injection pump.

6. Device according to claim 1, characterized in that it comprises fuel-leakage sighting means interposed between said hood and said collecting vessel.

7. Device according to claim 6, characterized in that said sighting means comprises a tubular member ending in a substantially vertical whistle and opening freely into an enclosure provided with a sighting window.

8. Device according to claim 1, characterized in that said hood is in the form of a cone-shaped cap ending with a tubular portion fitted through the medium of an interposed seal on the head of the injection pump, the said portion being provided with an abutment shoulder by which it abuts against said head, whereas the connection between said delivery pipe and said head takes place through the medium of a coupling located within said hood. 

1. Device for collecting and detecting fuel leakage in a fuel delivery pipe surrounded by a sheath and connecting an injection pump with the injector of the corresponding cylinder of an internal combustion engine, said device comprising a sealed hood covering the head of the injection pump and through which pass said delivery pipe and said sheath, the latter terminating in the internal volume of said hood, leak-fuel and discharge means for discharging the leak-fuel accumulated in said internal volume, said leak-fuel discharge means comprising a collecting vessel connected with the internal volume of said hood and provided with a warning device.
 2. Device according to claim 1, characterized in that said collecting vessel is provided with a level detector comprising a float mounted on a pivotable arm and adapted to aCtuate said warning device.
 3. Device according to claim 1, characterized in that said collecting vessel is provided with a large-sized opening for the overflow of fuel resulting from important leakage.
 4. Device according to claim 1, characterized in that said collecting vessel is provided at its bottom with a small-sized opening for the outflow of fuel resulting from leakage of small importance.
 5. Device according to claim 1, characterized in that said leak-fuel discharge means comprise a discharge pipe opening into the upper portion of said collecting vessel and connected with the lower portion of the internal volume of said hood, said collecting vessel being located below the level of the injection pump.
 6. Device according to claim 1, characterized in that it comprises fuel-leakage sighting means interposed between said hood and said collecting vessel.
 7. Device according to claim 6, characterized in that said sighting means comprises a tubular member ending in a substantially vertical whistle and opening freely into an enclosure provided with a sighting window.
 8. Device according to claim 1, characterized in that said hood is in the form of a cone-shaped cap ending with a tubular portion fitted through the medium of an interposed seal on the head of the injection pump, the said portion being provided with an abutment shoulder by which it abuts against said head, whereas the connection between said delivery pipe and said head takes place through the medium of a coupling located within said hood. 